scp: ambiguous target error, with quotes, escape characters

Getting scp: ambiguous target while transferring file to white spaced folder name. I already tried solutions mentioned in here and also tried another solution on different question.

following commands are already tried,

1. scp -i "key" test.txt "user@host:E:New\ folder",
2. scp -i "key" test.txt user@host:"E:New folder",
3. scp -i "key" test.txt user@host:"'E:New folder'",
4. scp -i "key" test.txt "user@host:'E:New folder'",
5. scp -i "key" test.txt user@host:"E:New folder"

Still getting ambiguous target. Is there any mistake? how to overcome this ?