Stereochemistry of nucleophilic additions to the carbonyl group Communication 6. Reactions of 3-t-butylcyclohexanone

1964 ◽  
Vol 13 (6) ◽  
pp. 984-990
Author(s):  
A. M. Prokhoda ◽  
A. V. Kamernitskii ◽  
A. A. Akhrem
Keyword(s):  
Carbonyl Group ◽  
Group Communication ◽  
Nucleophilic Additions

Changing regioselectivity patterns in metal hydride reductions of unsymmetrically substituted cyclic anhydrides

1983 ◽  
Vol 61 (3) ◽  
pp. 439-441 ◽  
Author(s):  
Margaret M. Kayser ◽  
Judith Salvador ◽  
Peter Morand
Keyword(s):  
Carbonyl Group ◽  
Metal Hydride ◽  
Nucleophilic Additions ◽  
Substrate Molecule ◽  
Parent Molecule ◽  
Cyclic Anhydrides ◽  
Intrinsic Reactivity

A study of L- and K-selectride reductions of unsymmetrical cyclic anhydrides attached to six-membered rings and to bridged six-membered systems sheds a new light on the effect of the conformation of the substrate molecule on the regioselectivity of metal hydride reductions. Thus, in addition to intrinsic reactivity of the carbonyl group, the antiperiplanar effect, and steric congestion, the conformation of the parent molecule should be considered in predicting regioselectivity of nucleophilic additions to cyclic anhydrides.

Preparations of 6-substituted 6H-Dibenzo[b,d]thiopyrans and their S-oxides through nucleophilic additions to 6H-dibenzo[b,d]thiopyran-6-one

1983 ◽  
Vol 36 (4) ◽  
pp. 795 ◽  
Author(s):  
DD Ridley ◽  
MA Smal
Keyword(s):  
Carbonyl Group ◽  
General Procedure ◽  
Grignard Reagents ◽  
Nucleophilic Additions ◽  
Reactions With Nucleophiles ◽  
Acid Labile

Methods for the preparations of 6-substituted 6H-dibenzo[b,d]thiopyrans and the corresponding S-oxides were explored. The most general procedure involved the addition of Grignard reagents to 6H-dibenzo[b,d]thiopyran-6-one, whereupon 6-substituted 6H-dibenzo[b,d]thiopyran-6-ols were formed. The carbonyl group in the thioester thus behaved like an isolated ketone in its reactions with nucleophiles. The resultant dibenzothiopyran-6-ols were acid-labile, and dehydration products underwent further modification in some instances. Oxidation of the olefins afforded stable S-oxides. The dianion formed by reduction of dibenzothiophen also offered routes to 6-substituted 6Hdibenzo[b,d]thiopyrans, but the reactions of this dianion were non-regioselective and thus were of limited use.

PROSES KOMUNIKASI KELOMPOK DALAM METODE PEMBELAJARAN SENTRA UNTUK MEMBENTUK KEMANDIRIAN ANAK

Jurnal Common ◽  
2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Rismawaty Rismawaty ◽  
Sofie Aulia Rahmah
Keyword(s):  
Data Collection ◽  
Qualitative Method ◽  
Group Communication ◽  
Communication Process ◽  
Learning Method ◽  
Online Data ◽  
Analysis Techniques ◽  
Collection Data ◽  
Descriptive Approach ◽  
Using Data

Penelitian ini dilakukan untuk mengetahui proses komunikasi kelompok dalam metode pembelajaran sentra di TK Zaid bin Tsabit. Penelitian ini mendiskusikan tentang proses komunikasi kelompok. Metode penelitian yang digunakan dalam penelitian ini adalah Metode Kualitatif dengan pendekatan Deskriptif. Teknik pengumpulan data yang dilakukan peneliti ada dengan studi pustaka, penelusuran data secara online, wawancara, observasi serta dokumentasi dengan 3 orang informan kunci yaitu guru di TK Zaid bin Tsabit serta 3 informan pendukung yaitu Kepala TK Zaid bin Tsabit dan 2 orang tua murid. Uji keabsahan data dengan peningkatan ketekunan, triangulasi dan diskusi dengan teman sejawat, teknik analisis data menggunakan pengumpulan data, reduksi data, penyajian data, penarikan kesimpulan dan evaluasi.Hasil penelitian ini bahwa Proses komunikasi yang terjadi merupakan komunikasi langsung yang terjadi dua arah dan dilakukan terus menerus untuk membentuk kemandirian anak. Proses komunikasi yang terjadi dalam kelompok metode pembelajaran sentra membentuk kemandirian anak. Proses komunikasi yang dilakukan oleh guru kepada anak dilakukan dengan memberikan arahan-arahan kepada anak serta contoh dari arahan yang telah disampaikan oleh guru.Kesimpulan pada penelitian ini adalah metode pembelajaran sentra membentuk kemandirian anak lewat komunikasi yang dilakukan guru secara terus menerus, karna melalui pembelajaran sentra anak diminta untuk melakukan segala sesuatunya sendiri dalam pengawasan guru. Saran yang diberikan adalah guru harus lebih kreatif dalam memberikan materi pada metode pembelajaran sentra serta bersikap lebih tegas dalam mendidik anak dan melakukan komunikasi yang berkelanjutan dengan orang tua murid. --------------------------------------------------------------------------------- This study was conducted to determine the process of group communication in the center learning method at TK Zaid bin Tsabit. This study discusses the process of group communication. The research method used in this study is a qualitative method with a descriptive approach. The data collection techniques carried out by the researcher were with literature studies, online data searches, interviews, observation and documentation with 3 key informants namely the teacher at TK Zaid bin Tsabit and 3 supporting informants namely TK Head Zaid bin Tsabit and 2 parents. Test the validity of data by increasing perseverance, triangulation and discussion with colleagues, data analysis techniques using data collection, data reduction, data presentation, drawing conclusions and evaluations.The results of this study that the communication process that occurs is direct communication that occurs in two directions and carried out continuously to form the independence of children. The communication process that occurs in a group of central learning methods shapes children's independence. The process of communication carried out by the teacher to the child is done by giving directions to the child as well as examples of directions that have been delivered by the teacher.The conclusion of this study is that the central learning method shapes children's independence through continuous communication by the teacher, because through central learning children are asked to do everything themselves in the supervision of the teacher. The advice given is that the teacher must be more creative in giving material to the central learning method and be more assertive in educating children and making ongoing communication with parents.

Sign in / Sign up

Export Citation Format

Share Document