Jamuary 18, 1951.

Dr. S. F. Darling,
Department of Chenistry,
Lawrence College,
Appleton, Wis.

Dear Dr. Darling:

Thank you for your shipment of 160 gas. of cellobiose, just reeeived,
and for your letter deseribing some of the other compounds you have on
hand.

I would appreciate it if you could suggest a price for the following,
if they are available:

L-rhannogse 25 ~ 50 g.
L-arabinose 50 = 100 g.
D-arabinose 10 g.

I am also curious about the beta-methyl L~arabinogide. Dr. Link and I
had some discussion about the terminology of the rentosides which leaves
open the possibility that this refers to a compound homozerphous with
lactose. At one time, one of his students misunderstood what I was seoking
and prepared the sompondd so named, mep. 169°, but which is the melibiose
homomorph. I think his preparation involved condensation with MeOH in the
presence of HCl. The lactose analogue, in which I an interested, probably
could be made without too mach trouble from acetobrom-arabinose, If this
happens to be what you have, I would like very mich to tap your supply.

Yours sincerely,

Joshua Lederberg,
Asacelate Professor of Geneties