Synlett 2006(10): 1601-1603  
DOI: 10.1055/s-2006-941590
LETTER
© Georg Thieme Verlag Stuttgart · New York

Sequential Knoevenagel Reaction/Mislow-Evans Rearrangement Catalyzed by Heterogeneous Amine Grafted on Silica in Water, Leading to γ-Hydroxy-α,β-unsaturated Nitrile

Hisahiro Hagiwara*a, Kohei Isobea, Ayuko Numamaeb, Takashi Hoshib, Toshio Suzukib
a Graduate School of Science and Technology, Niigata University, 8050, 2-Nocho, Ikarashi, Niigata 950-2181, Japan
Fax: +81(25)2627368; e-Mail: hagiwara@gs.niigata-u.ac.jp;
b Faculty of Engineering, Niigata University, 8050, 2-Nocho, Ikarashi, Niigata 950-2181, Japan
Further Information

Publication History

Received 24 March 2006
Publication Date:
12 June 2006 (online)

Abstract

γ-Hydroxy-α,β-unsaturated nitrile was obtained by the reaction of α-arylsulfinylacetonitrile with aldehyde in water, which was catalyzed by N,N-diethylaminopropylated silica gel. The overall transformation proceeded via five sequential reactions, 1,2-addition of acetonitrile, dehydration (Knoevenagel condensation), isomerization of the double bond, rearrangement of sulfinyl group (Mislow-Evans rearrangement) and hydrolysis of sulfinyl ester. The reaction condition was mild such that the AcO, TBMDSO or OTHP group remained intact in the products.

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Typical Experimental Procedure.
To a suspension of NDEAP (168 mg, 0.17 mmol, amine loading 0.99 mmol/g) in H2O (1 mL) was added m-chloro-phenylacetonitrile (102 mg, 0.52 mmol) under nitrogen atmosphere. After being stirred for 10 min, (+)-citronellal (63 µL, 0.35 mmol) was added and stirring was continued for 6 h at r.t. After addition of 10% aq Et2NH (30 µL, 0.029 mmol), the mixture was stirred for 10 min. Product was triturated with EtOAc four times under vigorous stirring. The combined organic layer was evaporated to dryness and the residue was purified by medium pressure LC (eluent: EtOAc-n-hexane = 1:2) to give a diastereomeric mixture of (2E)-4-hydroxy-5,9-dimethyldeca-2,8-dienenitrile (54 mg, 80%).