Here's a process I've seen a couple times in various experimental organic chemistry books (including the one I've had for 25 years): the reduction of benzilic acid with red phosphorus and iodine. Also see US patent 3084099.
(https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000235880-file_goy2.jpg)From Elementary Laboratory Experiments in Organic Chemistry by R. Adams and J. R. Johnson, The Macmillan company, 1945
Also see:
Post 199822 (missing)
(PolytheneSam: "Re: better understanding", Newbee Forum) Post 199835 (missing)
(PolytheneSam: "Re: better understanding", Newbee Forum)
http://www.geocities.com/dritte123/PSPF.html
Synthesis of benzilic acid:
https://www.thevespiary.org/rhodium/Rhodium/chemistry/dimenoxadol.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/dimenoxadol.html)
(at the bottom of the page). What do you need it for?