88196-07-0

Upstream product

• 109385-09-3 [((E)-But-2-enyl)oxy]-acetic acid (1R,2S,5R)-5-methyl-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester 
• 89-82-7 pulegone 
• 65253-04-5 (-)-8-phenylmenthol 
• 80595-59-1 bromoacetic acid (-)-8-phenylmenthol ester 
• 590-18-1 (Z)-2-Butene 
• 84312-20-9 (1R,3R,4S)-8-phenylmenthyl glyoxylate 
• 624-64-6 trans-2-Butene 
• 72526-00-2 (-)-8-phenylmenthyl acrylate 
• 104197-95-7 (1R,2S,5R)-2-(1-methyl-1-phenylethyl)-5-methylcyclohexyl nitrooxyacetate 
• 76371-55-6 9-But-2-enyl-9-borabicyclo<3.3.1>nonane 
• 3200-73-5 trans-2-butenyltrimethylstannane 
• 35998-93-7 tri-n-butylcrotyltin 
• 17486-13-4 (Z)-crotyltrimethylsilane 
• 97371-54-5 (-)-(2S,5R)-5-Methyl-2-(1-methyl-1-phenylethyl)cyclohexanon 

Relevant academic research and scientific papers

Further Synthesis of Optically Active Verrucarinic Acid

Two new syntheses of verrucarinic acid ((2S,3R)-2,5-dihydroxy-3-methylpentanoic acid) and its derivatives, suitably protected for the further conversion to macrocyclic trichothecenes, are described.The first one makes use of a diastereoselective alkylation of a (-)-(S)-malic acid ester and the regioselective reduction of one carboxyl function to a methyl group.The second approach involves a stereoselective addition of an allylsilane to a chiral glyoxylate.

Asymmetric -Wittig Rearrangement Involving a Chiral Ester Enolate Terminus. A Chiral Synthesis of erythro-α-Hydroxy-β-alkyl Carboxylic Acid Derivatives

The title rearrangement of the (E-2-alkenyloxy)acetic esters derived from (-)-8-phenylmenthol has been shown to afford the corresponding 3-alkyl-2-hydroxy-4-pentenoic ester with an extremly high level of diastereoface selection (95-97percent de) along with a high erythro selectivity (90-93percent).

ASYMMETRIC INDUCTION IN THE ENE REACTION OF GLYOXYLATE ESTERS OF 8-PHENYLMENTHOL

We recently communicated (J.K.Whitesell, A.Bhattacharya, D.A.Aguilar and K.Henke, J.Chem.Soc.Chem.Commun. 989 (1982)) a highly efficient and effective method for the control of absolute stereochemistry through asymmetric induction in the ene reaction the chiral glyoxylate 1 with alkenes.We now have accumulated sufficient information on this process in terms of both its mechanistic details as well as its scope and applicability to a variety of situations that warrants a more complete presentation of these reactions.

STEREO- AND REGIOCONTROL OF ACYCLIC SYSTEMS VIA THE LEWIS ACID MEDIATED REACTION OF ALLYLIC STANNANES WITH ALDEHYDES

The reaction of crotyltrialkylstannanes (1) with aldehydes in the presence of BF3*OEt2 produces the corresponding erythro homoallyl alcohols (2) predominantly regardless of the geometry of the double bond. Further, the Lewis acid mediated reaction exhibits the enhanced Cram selectivity in comparison with other allylic organometallic reactions which proceed in the absence of Lewis acids.Use of AlCl3-i-PrOH as the Lewis acid entirely changes the reaction course; the linear adduct (12) is produced rather than the branched adduct (13).The reaction of 1-BF3*OEt2 system is applied to the short and stereoselective synthesis of the (+/-) Prelog-Djerassi lactonic acid (16) and (-) verrucarinolactone (19).

Enantio- and Diastereo-selective Reaction of But-2-enylstannane with Glyoxylate Esters and its Application to a Short Synthesis of Verrucarinolactone

The erythro-3-alkyl-2-hydroxypropionate unit in (4) is predominantly obtained via the reaction of but-2-enylstannane (2a) with glyoxylate esters (3) while the threo-isomer (5) is preferentially produced via 9-but-2-enyl-9-borabicyclononane (2b); the former reaction has been applied to the enantioselective synthesis of verrucarinolactone (6).

Asymmetric Induction. Ene Reactions of a Chiral Glyoxylate Ester

The acid-catalysed reaction of 8-phenylmentol glyoxylate with hex-1-ene and trans-but-2-ene provided the ene reaction products with asymmetric induction levels consistently above 93percent.