Baeyer–Villiger Oxidation of the Bicyclo[2.2.2]octanone System Revisited: Searching for a Modular Construction of Heavily Substituted Cyclohexanes Based onm-CPBA Mediated Selective Oxygen Insertion

2007 ◽  
Vol 2007 (24) ◽  
pp. 4116-4123 ◽  
Author(s):  
Laure Finet ◽  
Mohamed Dakir ◽  
Isabel Castellote ◽  
Siméon Arseniyadis
Keyword(s):  
Modular Construction ◽  
Oxygen Insertion ◽  
Villiger Oxidation

Baeyer-Villiger oxidation of Δ4-3-Oxo-steroids and 4,5-Epoxy-3-oxo-steroids. A route to some novel A-nor-steroids

1968 ◽  
Vol 21 (7) ◽  
pp. 1873
Author(s):  
JT Pinhey ◽  
K Schaffner
Keyword(s):  
Boron Trifluoride ◽  
Acidic Conditions ◽  
Oxygen Insertion ◽  
Acid Labile ◽  
Villiger Oxidation

Evidence is presented that the Baeyer-Villiger oxidation of Δ4-3-oxo-steroids yields enol-e-lactones which are further oxidized to β-epoxy-e-lactones. The latter are acid labile and rearrange to 5α-acyl-∂-lactones. The sequence appears to be stereospecific, and no 5β-acyl-∂-lactones could be isolated. Baeyer-Villiger oxidation of 4,5-epoxyoholestan-3-ones results in oxygen insertion between C3 and C4. The epoxy-e-lactones were not isolated, since they rearranged under the acidic conditions to give 5-acyl-4-oxacholestan-3-ones. The 5α-acyl epimers differ from the 5β-compounds, by undergoing an internal Claisen-type condensation to give A-norcholestans with a 2,5-lactone bridge. The photochemical, thermal, and boron trifluoride-catalysed conversion of the enol lactone (IIIa) into a-nor-5β-cholestan-3-one is reported.

ChemInform Abstract: A Study of the Regioselectivity of Oxygen Insertion in the Baeyer- Villiger Oxidation of Bicyclo(2.2.1)heptan-2-ones.

ChemInform ◽  
2010 ◽  
Vol 22 (45) ◽  
pp. no-no
Author(s):  
P. HAMLEY ◽  
A. B. HOLMES ◽  
D. R. MARSHALL ◽  
J. W. M. MACKINNON
Keyword(s):  
Oxygen Insertion ◽  
Villiger Oxidation

Exploring the Benefits of Early Contractor Involvement (ECI) and the Mechanism for Automated 5D BIM Quantification Process in Offsite Modular Construction

2016 ◽  
Author(s):  
Tochukwu Moses ◽  
David Heesom ◽  
David Oloke ◽  
Martin Crouch
Keyword(s):  
Effective Means ◽  
Cost Effective ◽  
Modular Construction ◽  
Automated Quantification ◽  
Building Information ◽  
Project Risks ◽  
Value Add ◽  
The Uk ◽  
The Impact ◽  
Level 2

The UK Construction Industry through its Government Construction Strategy has recently been mandated to implement Level 2 Building Information Modelling (BIM) on public sector projects. This move, along with other initiatives is key to driving a requirement for 25% cost reduction (establishing the most cost-effective means) on. Other key deliverables within the strategy include reduction in overall project time, early contractor involvement, improved sustainability and enhanced product quality. Collaboration and integrated project delivery is central to the level 2 implementation strategy yet the key protocols or standards relative to cost within BIM processes is not well defined. As offsite construction becomes more prolific within the UK construction sector, this construction approach coupled with BIM, particularly 5D automated quantification process, and early contractor involvement provides significant opportunities for the sector to meet government targets. Early contractor involvement is supported by both the industry and the successive Governments as a credible means to avoid and manage project risks, encourage innovation and value add, making cost and project time predictable, and improving outcomes. The contractor is seen as an expert in construction and could be counter intuitive to exclude such valuable expertise from the pre-construction phase especially with the BIM intent of äóÖbuild it twiceäó», once virtually and once physically. In particular when offsite construction is used, the contractoräó»s construction expertise should be leveraged for the virtual build in BIM-designed projects to ensure a fully streamlined process. Building in a layer of automated costing through 5D BIM will bring about a more robust method of quantification and can help to deliver the 25% reduction in overall cost of a project. Using a literature review and a case study, this paper will look into the benefits of Early Contractor Involvement (ECI) and the impact of 5D BIM on the offsite construction process.

Digitally Enabled Modular Construction for Promoting Modular Components Reuse: A UK View

2021 ◽  
pp. 102820
Author(s):  
Eleni Iacovidou ◽  
Phil Purnell ◽  
Konstantinos Daniel Tsavdaridis ◽  
Keerthan Poologanathan
Keyword(s):  
Modular Construction
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