[31053-11-9]  · C6H12OS  · 2-(Methylthio)tetrahydropyran  · (MW 132.25)

(methanethiol carbanion, HSCH2-, equivalent1)

Physical Data: bp 47-48 °C/5 mmHg;2 n20D 1.4910;3 colorless oil with minty aroma.

Preparative Methods: prepared in 84% yield by Pyridinium p-Toluenesulfonate-catalyzed addition of Methanethiol to 2,3-dihydropyran;1 this method is superior to an earlier procedure using HCl as catalyst.2 Deprotonation with t-Butyllithium gives 2-tetrahydropyranyl(thiomethyl)lithium [98194-89-9].1

Handling, Storage, and Precautions: stable to alkali; decomposed by dilute acid to methanethiol and 5-hydroxypentanal.2

Thiol and Disulfide Synthesis.

Reaction of 2-tetrahydropyranyl(thiomethyl)lithium with benzaldehyde, n-heptyl iodide, 1,6-dibromohexane, Benzyl Bromide, t-Butyldimethylchlorosilane, or Dichlorodimethylsilane, followed by hydrolysis of the adduct with Silver(I) Nitrate or Mercury(II) Chloride followed by Hydrogen Sulfide or Hydrogen Chloride gives, respectively, PhCH(OH)CH2SH (100%), n-C8H17SH (60%), HS(CH2)8SH (76%), PhCH2CH2SH (93%), t-BuMe2SiCH2SH (77%), and Me2Si(CH2SH)2 (22%). If the adduct is treated instead with iodine, disulfides instead of thiols result.1 Repetitive treatment of the initial adduct with base and electrophile has been used to prepare (Me3Si)3CSH.1 Application of these procedures to the synthesis of cis- and trans-3-mercaptocyclobutanol has been reported (eq 1).4 Related work has been reported for the tetrahydropyran derivative of diphenylmethanethiol.5

1. Block, E.; Aslam, M. JACS 1985, 107, 6729.
2. Kipnis, F.; Ornfelt, J. JACS 1951, 73, 822.
3. de Hoog, A. J.; Havinga, E. RTC 1970, 89, 972.
4. Block, E.; Laffitte, J.-A.; Eswarakrishnan, V. JOC 1986, 51, 3428.
5. Berg, J. M.; Holm, R. H. JACS 1985, 107, 917.

Eric Block

State University of New York at Albany, NY, USA

Copyright 1995-2000 by John Wiley & Sons, Ltd. All rights reserved.