156137-92-7

Upstream product

• 152459-05-7 (+)-<2'R,6R,7R>-6-methyl-7-(6-methylhept-2-yl)-2-(phenylsulfonyl)bicyclo<4.3.0>-1,4-nonadiene 
• 66251-18-1 Grundmann's ketone 
• 108-98-5 thiophenol 

Downstream Products

• 96685-52-8 (+)-<1R,2'R,5R,6R,9R>-1-methyl-9-(6-methylhept-2-yl)-5-(phenylsulfonyl)bicyclo<4.3.0>nonane 
• 152458-96-3 (+)-<1R,2'R,5S,6R,9R>-1-methyl-9-(6-methylhept-2-yl)-5-(phenylsulfonyl)bicyclo<4.3.0>nonane 

Relevant academic research and scientific papers

Vitamin D3 synthetic studies. A three-step procedure for the preparation of (+)-(1R,5R,6R,9R,2'R)-1-methyl-9-(6-methylhept-2-yl)-5- (phenylsulfonyl)bicyclo[4.3.0]nonane from Windaus-Grundmann ketone

A procedure is described for the preparation of vitamin D3 key fragment (+)-(1R,5R,6R,9R,2'R)-1-methyl-9-(6-methylhept-2-yl)-5- (phenylsulfonyl)bicyclo[4.3.0]nonane 3 in three steps and 55% overall yield from Windaus-Grundmann ketone 5.

Vitamin D3 synthetic studies. Intramolecular Diels-Alder approaches to the CD-ring fragment

The enantiospecific synthesis of the vitamin D3 CD ring fragment 3 is reported. Key steps are the diastereoselective allylation of a norephedrine/dihydrocitronellic acid-derived oxazolidinone, and the intramolecular Diels-Alder reaction of a sulfonyl-substituted dienyne. The analogous cycloaddition reaction of a trienylsulfone substrate is shown to give products having the incorrect stereochemistry for vitamin D3 synthesis.