Enantioselective synthesis of alpha-ionone derivatives using an anti S(N)2' substitution of functionalized zinc organometallics.
[reaction: see text] The allylic substitution of sterically hindered (2-iodocycloalkyl)phosphates proceeds with complete anti S(N)2' stereoselectivity with mixed diorganozincs of the type RZnCH(2)SiMe(3) in the presence of CuCN.2LiCl. Only the group R of the copper-zinc reagent is transferred in the allylic substitution. This method was used to prepare odoriferous substances such as (R)-alpha-ionone in 97% ee and (R)-dihydro-alpha-ionone in 98% ee.
Soorukram
Darunee
D
Department Chemie, Ludwig-Maximilians-Universität, Butenandtstrasse 5-13, 81377, München, Germany.
Knochel
Paul
P
D002384:Catalysis; D007202:Indicators and Reagents; D015394:Molecular Structure; D045792:Norisoprenoids / Q000138:chemical synthesis* / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D009943:Organophosphorus Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry
D007202:Indicators and Reagents; D045792:Norisoprenoids; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; C011879:alpha-ionone; D015032:Zinc