237406-06-3

Upstream product

• 185851-21-2 (-)-N-(α-methylbenzyl)-3-bromo-2,2,4-trimethylcyclohex-3-ene carboxamide 
• 185851-20-1 3-bromo-2,2,4-trimethylcyclohex-3-ene carbonyl chloride 
• 4773-87-9 3-bromo-2,4-dimethylpenta-1,3-diene 
• 2627-86-3 (S)-1-phenyl-ethylamine 
• 185851-37-0 3-bromo-2,2,4-trimethylcyclohex-3-ene-5-one carboxylic acid 
• 185851-32-5 (+)-N-(α-methylbenzyl)-3-bromo-2,2,4-trimethylcyclohex-3-ene carboxamide 

Downstream Products

• 237406-08-5 (+)-methyl 3-bromo-5α-hydroxy-2,2,4-trimethylcyclohex-3-ene carboxylate 
• 185851-38-1 (+)-methyl 3-bromo-2,2,4-trimethylcyclohex-3-ene-5-one carboxylate 
• 185851-37-0 3-bromo-2,2,4-trimethylcyclohex-3-ene-5-one carboxylic acid 

Relevant academic research and scientific papers

Taxane diterpenes 5: Synthesis of the A- and C-rings: An unusual rearrangement of an N-hydroxyimino lactone

Ring A of taxol was synthesized from the bromodiene 5 and acryloyl chloride to give 6, which was resolved by separation of diastereomers 7. Allylic oxidation of 7 gave 8, which on deprotection, esterification and reduction gave 11. Heating 11 followed by reduction and protection gave 13. The C-ring component was made using asymmetric Birch reduction methodology combined with standard functional group manipulations to give 28. Combining 13 and 28 gave 29, which was converted into 33. Thermolysis of 33 did not generate a nitrile oxide but rather ionized to an oxydienyl cation, eventually leading to 34.

Concise synthesis of taxol A-ring components: Remote diastereoselective additions of alkenyl lithiums to aldehydes

The acid chloride 6 provides access to 7 (R,S and S,S) which upon bromine-lithium exchange undergoes remarkably highly diastereoselective additions to aldehydes; 7 is also readily elaborated into the acetal 10.