Table 1.

Deuteration experiments

Entry	Xanthate	Productse	Solvent	D %
1	1a	1b	Et2O	0
2	1a	1b + 1c	CDCl3/CD3OD a	88
3	1a	1b + 1c	(CH2Cl)2/CD3OD a	85
4	1a	1b + 1c	(CH2Cl)2/CH3OD a	76
5	1a	1b + 1c	(CH2Cl)2/D2O a	83
6	1a	1b + 1c	THF/D2O a	83
7	1a	1b + 1c	THF 3 h, then D2O a	<1
8	1a	1b + 1c	3 h then CH3OD a	6
9	1a	1b + 1c	20 min then CH3OD a	17
10	1a	1b + 1c	THF; D2O/H2O = 25 equiv/25 equiv	6
11	1a	1b + 1c	H2O/D2O = 5 equiv/100 equivb	66
12	1a	1b + 1c	H2O/D2O = 20 equiv/80 equivb	32
13	2a	2b + 2c	(CH2Cl)2/CH3ODa	93f
14	1a	1b + 1c	CDCl3c	57g
15	1a	1b + 1c	CDCl3c/D2Od	83
16	1a	1b + 1c	C6D6c	<1
17	1a	1b + 1c	C6D6c/D2Od	70
18	1a	1b + 1c	CDCl3c/H2Od	3
19	1a	1b + 1c	THF-d8	<1h

Reduction of S-alkylxanthates (0.3–0.4 mmol) with Et₃B (5 equiv from a commercial solution in hexanes)/dry air for 3 h, unless otherwise stated. Xanthates were reduced according to method A except in experiment 13 where method B was used. ^a 50 equiv of deuterated methanol or water were used. ^b No other organic solvent than hexanes from the commercial Et₃B solution. ^c Reactions performed with freshly prepared 1M solutions of pure Et₃B in CDCl₃ or C₆D₆. ^d 5 equiv of D₂O or H₂O. ^e All the yields in pure 1b + 1c are superior to 61% except for experiment 16 (yield 40%). ^f Yield 2b + 2c = 70%. ^g When the reaction was performed with CDCl₃ dried over K₂CO₃, the deuterium incorporation fell to 15.8%. ^h This experiment was carried out twice.