134436-06-9

Upstream product

• 134436-05-8 Acetic acid (E)-1-methyl-3-(2,6,6-trimethyl-cyclohex-1-enyl)-1-vinyl-allyl ester 
• 79-77-6 (E)-β-ionone 
• 38987-91-6 [(2E,4E)-3-Methyl-5-(2,6,6-trimethyl-cyclohex-1-enyl)-penta-2,4-diene-1-sulfonyl]-benzene 
• 59057-30-6 (1E)-1-(2,6,6-trimethylcyclohex-1-enyl)-3-methyl-1,4-pentadien-3-ol 
• 14398-40-4 (E)-2-methyl-4-(2,6,6-trimethyl-1-cyclohexenyl)-2-butenal 
• 75-77-4 chloro-trimethyl-silane 
• 55497-47-7 (e)-3-methyl-2-(2',6',6'-trimethylcyclohexenyl)-penta-1,3-diene 
• 134436-09-2 [(2E,4E)-1-Benzenesulfonyl-3-methyl-5-(2,6,6-trimethyl-cyclohex-1-enyl)-penta-2,4-dienyl]-trimethyl-silane 

Relevant academic research and scientific papers

The organoalkali route to vitamin A and β-carotene

The reductive cleavage of methyl vinyl-β-ionyl ether (1) or the deprotonation of 3,2′,6′,6′-tetramethyl-5-(1-cyclohexenyl)-1, 3-pentadiene (2) gives rise to an organometallic C15 species that combines selectively with a variety of electrophiles at the terminal chain position. Its reaction with aldehydes, however, is less clean. In particular, (E)-β-formyl-2-butenyl acetate gives the expected adduct 7a and, after dehydration, vitamin A acetate only in poor yield. The same is true for the analogous reaction with 2,7-dimethyl-2,4,6-octatriendial, which ultimately affords βcarotene. Vitamin A acetate can also be prepared, this time in moderate yield, by functionalization through consecutive deprotonation, borylation, oxidation and acetylation of a C20 pentaene hydrocarbon having the required skeleton. Both the C15 and the C20 organometallic key intermediates adopt spontaneously a zigzag-like outstretched conformation which, upon electrophilic trapping, directly and exclusively leads to the all-(E) configuration.

A novel regioselective synthesis of allylsilanes

The anions derived from allyl sulfones were silylated in the α-position. Reductive desulfonylation gave the desired allylsilanes regioselectively