Formaldehyde → 3-(Cyclohex-1-en-1-yl)prop-2-yn-1-ol

First, the appropriate alkynyl alcohols are synthesized. To produce the particular compositions disclosed herein, 1-Ethynylcyclohexene, for example, is deprotonated with butyl lithium and then condensed with paraformaldehyde (Brandsma and Verkruijsse). By this process, 3-Cyclohexenyl-2-propyn-1-ol was produced in 82% yield (Baudouy, et al.). This compound had been reported previously without complete spectroscopic data (Baudouy). 1-Ethynylcyclohexene (3.00 g, 28.6 mmol) was dissolved in diethyl ether (125 mL) and cooled to −78° C. 2.5 M n-butyllithium in hexane (12.4 mL, 31.1 mmol) was added dropwise. The solution was allowed to stir at −78° C. for 1.5 h and then paraformaldehyde (1.70 g, 56.5 mmol) was added. The reaction mixture was allowed to warm to 25° C. overnight. The mixture was poured into sat. NH4Cl solution (125 mL) and then extracted with diethyl ether (3×50 mL). The ether extracts were dried with MgSO4 and the solvent was removed under reduced pressure. The crude product was purified by column chromatography on silica gel using 1:1 diethyl ether/pentane to yield a light yellow oil (3.17g, 23.3 mmol, 82.4%). 1H NMR (CDCl3): 6.09 (m, 1 H), 4.35 (s, 2 H), 2.07 (m, 4 H), 1.62-1.57 (m, 5 H). EI HRMS (m/e) called for (M+)(C9H12O) 136.0888, found 136.0894.

1. customTo produce the particular compositions

ORD record

ord-8d3187a4e07c49c7b896d60d163ed349

Source dataset

uspto-grants-2001_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06242478B1