Alfred Abraham Knopf Sr. (September 12, 1892-August 11, 1984) was an American publisher of the 20th century, and founder of Alfred A. Knopf, Inc. His contemporaries included the likes of Bennett Cerf and Donald Klopfer, and (of the previous generation) Frank Nelson Doubleday, J. Henry Harper and Henry Holt. Knopf paid special attention to the quality of printing, binding, and design in his books, and earned a reputation as a purist in both content and presentation.
FROM https://en.wikipedia.org/wiki/Alfred_A._Knopf_Sr.

Asked how to say his name, Knopf told the Literary Digest:
“Sound the k: k’nupf.”

Obituary in New York Times~
http://www.nytimes.com/1984/08/12/obituaries/alfred-a-knopf-91-is-dead-founder-of-publishing-house.html
The history of the house of Knopf~
http://www.randomhouse.com/knopf/about/index.html