the reaction of triphenylphosphinemethylenes with lithium aluminum hydride

THE REACTION OF TRIPHENYLPHOSPRINEBX'RYLENES

WITH LITHIUM ALUMINUM RYDRIDE

Martin Saunders and Gracie Burchman~

Sterling Chemistry Laboratory, Yale University, New Haven, Corm.**

(Received 26 January 1959)

ALTHOUGH triphenylphoaphineacylmethylenea have been known for some time,'

Wittig'e recent preparation of the simpler analoge has been of interest

because of their eynthetio utility.2

We wish to report a new reaction which these compounds undergo on

treatment with lithium aluminum hydride, When the triphenylphosphine-

methylenee, (C6H5)3P-CHR: (I) R=H, (II) R= COCH3, (III) R-COC6H5,

(IV) R=COC(CH3)2COCH(CH3)2 3

l United States Public Health Predoctoral Fellow of the National Institute of Arthritis and Metabolic Diseases, 1957 - 59.

** Contribution No. 1518 from the Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut.

A. Miohaelie and E. Kohler, Ber. Dtrrah. Chem. Ges, 22, 1566 (1899).

G. Wittig and U. Bchollkopf, Ber. Dteoh. Chem. Gee, :I, 1318

(1954)1 G. Wittig, Exwrientia 22, 41 (1956); G. Wittig,

Azwer. Chem, pi, 505 (1956); F. Ramire% and S. Dershowltz,

J. Org. memm, 22, 41 (1957).

Preparation and structural information are desoribed in

Ph. D. Theeie of P. Saunders, Harvard University (1956).

Triphenylphosphlneue~lenos 9

ware rtlrred with exoess reagent in either-tetrahydrofuran, produotr were

obtained on hydrolysis in whloh hydrogen had been added to the methylone

carbon and whioh had loot bensene.

(I) gave a liquid phosphine uhioh fielded dimethyldiphenylphosphon-

fun Iodide upon treatment Seth methyl iodide (2meldf m.p. 249.5-2510,

1it.4 241°. Found: C, 48.9f H, 5.Of P, 9.2. Cal% for C14E16PI 8 c, 49.11

B, 4.7f P, 9.d). Illu phosphiner readily oxldised on standing In air to

orysblllne phosphine oxides.

(II) 6aw (C6%,)2P(0)cH2CocB5 (ltieldf m.p. 127-1290 A, 5.84

(C-O), 8.4W (P +-O -). Found: C, 70.28 8, 6.31 P, 12.0. Clfi502P

reqdrea C, 69.88 H, 5.91 P, 12.0%).

(III) @m (C6E5&P(0)CI$COC6H5 (46 jieldf 8.~. 140-140.5°.

L5.96 (C-O), 8.47~ (P+-O-1. Found: C, 74.98 H, 5.61 P, 10.0.

C&70$ mamm C# 75.Of He 5.45 P, 9.796).

(Iv) eve (c6E5)2p(0)~c~(~~)2~OE~(~)2 (54 k

Y5 - Y7.5O. x, 2.96 (OH), 5.87 (C - 01, 8.47 v @+

Found:

P, 8.6

C, 70.7, He 7.61 P, 8.9. C21&$3P

$>.

requlror C, 70.6r

after reaotlon In The 18olatlon of ketonio produotr

rI*ldf ma.

- o- 1.

E, 7.6

the preaenao

of excess LiAlE 4 is most readily l rplloable In tense of an enolate salt

uhiohle reslrtant to further attaoh. Suohan enolate might be formed by

either attaah of the LUllI on the phony1 group produoing bensona dlreot3J

or addition to the phosphorour atom giving a pentavalent Intermediate whloh

aan lose bbnsbnb in a manner rlmllar to thelorr ofbiphenylfrompenta-

phenMwhorow5

4 A. Hiohaells and A. Link, Llebinr Aan% gOJ, 193

5 0. Wittlg and 0. Coirsler, Jlebl&s Ann, a, 44

(1891).

(1953).